fix(10-04): prettier format + remove unnecessary type assertions

- Run prettier on all new/modified PWA files (CredentialSheet, SetupBanner, AdminPage, admin.spec.ts)
- Remove unnecessary 'as React.RefObject<HTMLElement | null>' casts flagged by @typescript-eslint/no-unnecessary-type-assertion
- Format pre-existing API files from Plans 02/03 (me.ts, user.test.ts, requireAdmin.test.ts, me.test.ts)
- All 270 API tests + 191 PWA vitest tests pass; lint/typecheck/build clean

apps/pwa/src/components/SetupBanner.tsx

@@ -30,6 +30,7 @@ import { CredentialSheet } from './CredentialSheet.js';
 
 export function SetupBanner() {
   const [sheetOpen, setSheetOpen] = useState(false);
+  // Use HTMLButtonElement for the ref (assignable to the CredentialSheet's HTMLElement trigger)
   const ctaRef = useRef<HTMLButtonElement>(null);
 
   const meQuery = useQuery({
@@ -124,7 +125,7 @@ export function SetupBanner() {
         onClose={() => setSheetOpen(false)}
         mode="self-service"
         memberName={memberName}
-        triggerRef={ctaRef as React.RefObject<HTMLElement | null>}
+        triggerRef={ctaRef}
       />
     </>
   );